In recent years, along with development of analytical methods, a method of allowing biological microparticles such as cells and microorganisms, microparticles such as microbeads and the like to flow through a flow path and individually measuring the microparticles and the like and analyzing or sorting the measured microparticles and the like at a step of allowing to flow.
As a representative example of such a method, technological improvement of an analytical method referred to as flow cytometry is advancing rapidly. The flow cytometry is an analytical method of analyzing and sorting the microparticles by allowing the microparticles to be analyzed to flow in a state arrayed in fluid and applying laser light and the like to the microparticles to detect fluorescence and scattered light emitted from each of the microparticles. A device used for this flow cytometry is called as a flow cytometer.
Furthermore, in recent years, full automation of a microparticle measuring device such as the flow cytometer is advancing; for example, a device which automatically samples from a plurality of containers (test tube, microtube, well and the like) holding different samples and measures is developed.
For such a device, for example, in Patent Document 1, a technology capable of suppressing mixture of other particles and analyzing the particles with a high degree of accuracy by providing a particle analyzing device including a flow cell provided with an introduction unit in which sample solution containing particles to be analyzed and sheath solution are introduced and a detecting unit through which a layer flow including the sample solution and sheath solution flows, a sample solution introducing member in which a suction nozzle arranged immediately below the flow cell so as to be movable in a forward direction and a backward direction with respect to a sample solution introducing direction to suck the sample solution and a sample solution introduction nozzle arranged in the introduction unit of the flow cell which discharges the sucked sample solution into the flow cell, and a movement restricting mechanism which restricts a movement amount of the sample solution introducing member.